Controlling means for lens edging machine



Nov. 15, 1955 l. B. LUECK ETAL CONTROLLING MEANS FOR LENS EDGING MACHINEFiled March 23, 1953 2 Sheets-Sheet l A416 0h m: PO/2.200 h INVENTORS l.B. LUECK G.C.SCHELL|NG flmm ATTORNEY Nov. 15, 1955 I. B. LUECK ETAL2,723,501

CONTROLLING MEANS FOR LENS EDGING MACHINE Filed March 23, 1953 2Sheets-Sheet 2 INVENTORS |.B.LUECK BY G.C.SCHELI ING ATTORNEY UnitedStates Patent Irving B. Lueck, Perinton, and George C. Schelling,Irondequoit,.N. Y., assignors .to Bausch & Lomb Optical Company,Rochester, N. Y., a corporation of New York t Application March 23,1953, Serial No.343,87 6

. 8 Claims. .(Cl. 51-101) This invention relates to improvements in alens edging machine and more particularly it has reference to a noveldevice for substantially increasing the effective working area of a lensedging wheel.

In prior lens edging machines, the face of the grinding wheel is notworn down uniformly and hence, after some use, ledges of abrasiveareformed at the boundaries thereof.. These ledges of abrasive performno useful. grinding function and due to their protrusion above theregular grinding, face many. lenses are broken. Attempts have been madeto minimize this wasted grinding area by providing the grinding machineswith adjustments on the grinding wheel or on the moving lens carriage sothat the edge of a lens would be moved across the entire grinding face.These adjustments required that for each lens of different thickness adifferent setting be made so as to vary therelative movement between thegrinding wheel and the lens carriage to permit the lens to travelsubstantially to the boundaries of the grinding face. However, becauseof the time consumed and the bother involved, the operators usuallyneglect to make such adjustments with the result that. the grindingwheel is not worn down uniformly across its grinding face. I .It is,therefore,an object of this invention to provide a machine foredginglenses that will overcome the abovementioned disadvantages and beconvenient and efficient in operation. Another object of the inventionis to provide such a machinehaving sensitive controlling means forreversing the direction of travel of a lens across the face of agrinding wheel. .Still another. object of the invention is to provide amachine having a lens that travels substantially all the way across theface of a grinding wheel to effectively eliminate unused grinding areason the grinding face. A further object of the invention is to provide amachine in which one side of the lens activates the mechanism forreversing the direction of movement of. the lens across the grindingface therebyeliminating the need for individual adjustments of the wheelor lenscarriage.

Other objects and advantages pertaining to the construction of thedevice and'to the form and relation of parts thereof will more readilyappear from the following description taken in connection with theaccompanying drawings, in which:

Fig. 1 is a vertical-sectional view of a lens edging machine embodyingour invention.

Fig. 2 is a schematic view showing the means for controlling movement ofthe lens carriage.

Fig. 3 is an enlarged sectional view taken along the line 33 in Fig. 1showing a detail of the hydraulic pump.

Fig. 4 is an enlarged sectional view taken along the line 4-4 in Fig.1,'showing a detail of the reversing arrangement.

Fig. 5 is a view partially in section along the line 55 in Fig. 2,showing a lens just contacting one of the reversing fingers. j t

A main stationary frame (not shown) carries a rotatable grinding wheelwhich has acylindrical grinding face 11 having boundaries 12 and 13 onopposite sides there- ICC of. A power means (not shown) drives both thegrinding wheel 10 and the shaft 15. On the shaft 15 is a pulley 16 whichdrives a belt 17 that extends to and drives a pulley 18 keyed on asleeve 19 rotatably supported in an arm 20 which is secured to a baseplate 21 fastened on the main frame transversely to and in proximity tosaid grinding wheel 10. The sleeve 19 is clutched on the shaft 22 by aclutch mechanism 23 operated by a lever (not shown) which is used toseparate clutch drive plate 24 and clutch disk 25. The shaft 22 isjournaled at one end in bushing 26 of arm 27 and has a spline at 28 nearits other end for slidably fitting into a mating portion in clutch disk25.

A carriage 29 is mounted on the base plate 21 so as to be slidable in aplane parallel to the axis of the grinding wheel 10 on the shaft 22which extends through said carriage. The carriage 29 has at each endupwardly extending portions 30 which carry bearings 31 in which theshaft 22 is rotatably mounted. Blocks 32 and 33 are secured on the shaft22 against the opposite ends of the carriage so that when the carriageis moved longitudinally the rotating shaft 22 will be movedlongitudinally also and will continue to be rotated by the pulley 18through the clutch 23 and spline 28.

' A frame 34 is pivotally mounted upon the carriage 29 about the shaft22 so as to rock transversely of the carriage and move longitudinallywith the carriage, but has no longitudinal motion independent of thecarriage. The frame 34 has two upstanding portions 35 and 36 forrotatably supporting, respectively, the two aligned shafts 37 and 38.Secured to shaft 37 is a gear 39 that is driven by a pinion 41 on theshaft 22. Likewise, shaft 38 has a gear 40 driven by a pinion 42 on theshaft 22. It is obvious from this construction that when the shaft 22 isrotated the pinions 41, 42 will drive gears 39, 40 to rotate the shafts37 and 38 simultaneously.

The shaft 38 is rotatably mounted in portion 35 with a bearing 43 oneach side of the gear 40. Removably fastened at the outer end of theshaft 38 is a pattern cam 44 which is shaped to conform to the desiredshape and size of a lens 45 to be edged. A fixed block 46 is secured tothe arm 27 against which the cam pattern 44 rides to permit the lens 45to be shaped the same as the cam pattern 44. Attached at one end to apin 35" on the upstanding portion 35 of the frame 34 is a spring 44which is adapted to rock said frame 34 toward the main stationary frameon which the other end of the spring 44 is attached to a pin 37'. Thisrocking of the frame 34 will bring the edge of the lens 45 againstgrinding wheel 10 so that the lens is ground to the shape of pattern 44.When the lens has been edged to the point where the cam 44 contacts theblock 46 continually through a complete revolution of the cam, the lensis then of the proper peripheral size and further grinding does not takeplace.

The lens 45 is held between the rubber pads 48 and 50 which are carriedby the enlarged ends 47 and 49 formed, respectively, on the ends ofshafts 38 and 37. The shaft 37 is free to move lengthwise in sleeves 51and 52 and is urged by spring 53 in the direction that will hold thelens 45 between the pads 48 and 50. A lever 54 is pivoted on upstandingportion 35 to engage with collar 55 on shaft 37, so that by pivoting thelever against the force of the spring, a lens can be removed from orinserted between the pads 48 and 50.

The means for driving and reversing the lens carriage 29 transversely ofthe grinding face 11 is-shown in Figs. 1, 3 and 4. Attached to baseplate 21 is a piston cylinder 58 having fluid ports 59 and 60communicating with ports 61 and 62 in thebase plate 21 and having apiston 63 attached to piston rod 57. The piston rod 57 extends axiallyboth ways beyond the cylinder 58 into contact with the abutments 56depending downwardly from the carriage 29. Fitted into opening 64 inbase plate 21 is a pump housing 65, for receiving a rotary valve 66, asis best shown in Fig. 3, having an eccentric bore 67 in which is mounteda rotary impeller 68 coaxial with the axis of the valve but eccentricwith respect to the bore 67. The impeller 68 has blades 69 spring-biasedoutwardly toward the walls of the bore 67 by springs 70. The valve 66rotates freely in bore 67 and is provided with ports 71, 71 on oppositesides of the housing 65 to communicate with the ports 61 and 62 in thebase plate and 59 and 60 in the cylinder. The impeller 68 is attached toshaft 72 which is fastened to worm wheel 73 which meshes with worm gear74 on rotating shaft 15. Rotation of the shaft 15 drives the impeller 68to pump fluid from one side of piston 63 through the ports and into theother side of the piston to drive the piston in the direction of flow offluid.

Referring to Figs. 1, 2, 3 and 4, a pawl 76 comprising ends 77, 78 andattached lever 79, is mounted in cap 65 in the lower portion of baseplate 21 to pivot about the axis of a shaft 80 lying in the same planeas and at right angles to the axis of the impeller shaft 72. As theshaft 80 is rocked about its axis, the opposite ends 77 and 78 of thepawl 76 are alternately forced into the path of a lever 81, as shown inFig. 4, which is eccentrically pivoted at 82 to the face of the rotaryvalve 66 so as to rotate with said valve. The lever 81 is provided witha gripping portion 83 for frictional engagement with the innercylindrical walls of the cap 65' when the lever 81 encounters either end77, 78 of the stop pawl 76. Lever 81 is spring-pressed in the directionof rotation of the valve 66 by spring 84 which releases the grippingportion 83 from the cap 65' when ends 77, 78 of pawl 76 are pivoted outof contact with the lever.

The friction produced by the impeller 68 and blades 69 Within the valve66, along with the flow of fluid through the valve 66 tends to rotatethe valve 66 and attached lever 81. This rotation of the valve 66 isinterrupted by the lever 81 on the valve engaging with either end 77, 78of pawl 76. By rocking the ends 77, 78 of pawl 76 out of contact withthe lever 81, the valve 66 and attached lever 81 will rotate 180 untilthe lever 81 contacts the other end of pawl 76. This rotation of thevalve 66 will reverse the ports 71, 71' in the system and the pumpingaction of impeller 68 will pump the fluid in the opposite direction fromits previous flow, thereby reversing the direction of movement of thepiston 63 and its attached rod 57 so that the movement of lens carriage29 is reversed.

The mechanism which has been described is well known in the prior art.In such prior devices, the direction of movement of the lens carriage isreversed by the engagement of the lever 79 with a pair of oppositelypositioned stops which are adjustable in accordance with the thicknessof the lens to be edged so that the entire surface of the grinding wheelwill be contacted by the edge of the lens so the grinding surface isworn down uniformly. The operators, however, usually neglect to makesuch adjustments with the result that the grinding surface soon hasledges formed adjacent its edges. With our new device, the travel of thelens carriage is automatically controlled by the thickness of the lensso that individual adjustments need not be made for each lens.

In our controlling mechanism, the lever 79 engages collar 85 carried bythe core 86 of the solenoids 87 and 88 which are held by brackets 67' tothe plate 21 by bolts 75 extending through the brackets 67', cap 65 andvalve housing 66. As the solenoids are alternately energized the core 86is reciprocated from one side to the other so that the lever 79 and pawl76 are moved. The energizing of alternate solenoids is produced by amech anism which will now be described.

Slidably supported in uprights 91, 92 is a shaft 93 having alongitudinal slot 94 adapted to receive a lug 95 downwardly urged byspring 96 which is held by a cap 97 on upright 92. The spring pressedlug 95 coacts with the slot 94 to prevent shaft 93 from rotating aboutits axis and to resist, but not prevent, axial sliding of the shaft. Twofingers 98, 99 having bearing tips 100, 101 are fastened to shaft 93 byadjusting screws 102, 103 so that the tips 100, 101 will be adjusted tolie in close proximity to the outer boundaries 12, 13 of the grindingwheel 11 on opposite sides of said lens 45. Stop 104 retains lug 95 inthe slot 94 and the end of shaft 93 carries a screw 106 wherebyadjustments may be made between the end of the shaft 93.and a slidingpin 108 in switch 107, as well hereinafter be described.

A two pole switch 107 has a slidable pin 108 in alignment with shaft 93and the contact therebetween is adjusted by screw 106 so that the screw106 is always in end to end contact with pin 108 which contacts rightangled resilient strip 109 connected at one end 110 to one side 111 ofpower supply switch 112 through an insulated pole plug 113. When thelens 45 moves to its extreme left hand position in Fig. 2, the shaft 93and screw 106 are moved to their extreme left positions which permitsthe resilient strip 109 to move pin 108, still in contact with screw106, until the contact 114 of said strip 109 engages point 115 to make acomplete connection from the power supply switch 112, pole plug 113,strip 109, contact 114 to point 115, pole plug 117, solenoid 87 andcontact 116. In like manner, when lens 45 moves the shaft 93, screw 106and pin 108 to the extreme right hand position, the pin 108 biases strip109 upwards so that contact 114 engages point 118 to make a completeconnection from supply switch 112, pole plug 113, strip 109, contact 114to point 118, pole plug 120, solenoid 88 and contact 119.

Reciprocating about the axis of the rock shaft 80 between the contactmembers 116 and 119 is a snap arm 122 of snap actuator 123 which has anupper arm 124 rigidly attached to the rock shaft 80 extending through abearing portion in the cap 65' into rigid attachment with the pawl 76 ofthe controlling mechanism. The pawl 76, shaft 80 and upper arm 124 aremounted to pivot together about the axis of the shaft 80 so that theupper arm 124 of the snap actuator 123 will be reciprocated between thestops 125 as the lever 79 of pawl 76 is reciprocated by the solenoids 87and 88. Pivoting in the same plane as, but independent of the movementof the upper arm 124 of the snap actuator 123, is the snap arm 122 whichis electrically connected with the side 121 of the power supply switch112. A spring 126 is attached between upper arm 124 and snap arm 122 sothat when pawl 76 and shaft 80 move the upper arm 124 to a position onthe opposite side of the center line of snap arm 122, the arm 122 willbe moved from contact with member 116 into contact with member 119.

In operation, as the lens 45 of Fig. 2 is moved a slight distance to theleft from its disclosed position on the grinding face 11 of the lensedging machine, the peripheral part of the left face of the lens willmove the finger 98 and attached shaft 93 a slight distance to the left.This movement of shaft 93 will permit resilient strip 109 of the switch107 to move the pin 108 to the left so that contact 114 will engagepoint 115 to complete the circuit from the electrical supply sourceswitch 112 through plug 113, strip 109, point 115, plug 117, solenoid87, member 116, snap arm 122 and back to the switch 112. This willenergize the solenoid 87 to pull the solenoid core 86 and pawl lever 79to the left thereby pivoting pawl 76, rock shaft 80 and upper arm 124 ina clockwise direction. This movement of pawl 76 will release its end 77from lever 81 of valve 66 to initiate rotation of the valve by rotationof the impeller 68 within the valve 66. This initial rotation of thevalve will move the valve ports 71, 71' out of alignment with the pistonports 61, 62, respectively, to stop further movement of the lens to theleft. When upper arm 124 has been pivoted beyond the center line of snaparm 122, the spring 126 will pull arm 122 out of engagement with member116 to break the circuit through switch 107 and solenoid 87. The forceof spring 126 will not only move snap arm 122 into engagement withmember 119, but also will act through rock shaft 80 to pawl 76 tothereby position pawl end 78 in the path of lever 81 of valve 66. Pawlend 78 will stop the rotation of valve 66 when ports 71, 71' arealigned, respectively, with ports 62, 61 in such a position that fluidmay be pumped from the right to the left side of the piston 63 to drivethe carriage 29 with lens 45 to the right across the face of thegrinding wheel. When lens 45 contacts finger 99 and moves shaft 93 tothe right, the corresponding circuits are energized to again reverse thedirection of travel of the lens 45.

From the foregoing, it is obvious that we are able to attain the objectsof our invention and provide improved means for increasing the effectiveworking area of a lens edging wheel. The new controlling means for thereversing mechanism will substantially reduce the time consumingadjustments required by prior edging machines. The new controlling meansis automatically adjusted for lenses of any thickness, the outerperipheral face of each lens acting to control the reversing mechanism.Various modifications may obviously be made without departing from thespirit of our invention as pointed out in the appended claims.

We claim:

1. In a lens edging machine having a continuously rotating grindingwheel with a grinding face thereon, means for holding the edge of a lensin contact with the grinding face of said wheel, means for moving theedge of the lens across said grinding face, and reversing means forchanging the direction of movement of the lens across said grindingface, the combination of means controlling the reversing meanscomprising at least two spaced fingers disposed on opposite sides of thelens and respectively adjacent the boundaries of the grinding face inthe path of movement of the lens, and means operably connecting saidfingers to said reversing means whereby contact of the lens with eitherfinger will change the direction of travel of the lens across thegrinding face.

2. A lens edging machine comprising a continuously rotating grindingwheel having a grinding face thereon, means for holding the edge of alens in contact with the grinding face of said wheel, means for movingthe edge of the lens across said grinding face, reversing means forchanging the direction of movement of the lens across said grindingface, means for controlling said reversing means comprising at least twospaced fingers disposed respectively adjacent the boundaries of thegrinding face in the path of movement of the lens, and means operablyconnecting said fingers to said reversing means whereby contact of thelens with either finger will change the direction of travel of the lensacross the grinding face.

3. In a lens edging machine having a continuously rotating grindingwheel with a grinding face thereon, means for holding a rotating lenswith its edge in contact with the grinding face of said wheel, means formoving the edge of the lens across said grinding face, and reversingmeans for changing the direction of movement of said lens across thegrinding face, the combination of means for controlling the reversingmeans comprising a pair of spaced movable fingers, means operablyconnecting said fingers to said reversing means, said fingers beingdisposed on opposite sides of the lens and respectively adjacent theboundaries of the grinding face and in the path of said lens wherebysaid lens will move said fingers for controlling the reversing means tochange the direction of movement of the lens across the grinding face.

4. In a lens edging machine having a rotating grinding wheel with agrinding face thereon, means for holding a rotating lens with its edgein contact with said grinding face, and means for moving the edge ofsaid lens across said grinding face, the combination of a pair ofspaced, movable contact means lying respectively adjacent the boundariesof the grinding face on opposite sides of the lens, reciprocable meanssupporting said contact means in 'the path of said lens, switch meansconstructed and arranged to be engaged by said reciprocable means, andreversing means energized by the switch means for changing the directionof movementof said lens whereby as the lens approaches either boundaryof the grinding face itmoves one of said contact means so that thereciprocable means is moved into engagement with said switch means toenergize the reversing mea-ns thereby changing the direction of movementof said lens across said grinding face.

5. In a lens edging machine having a continuously rotating grindingwheel with a grinding face thereon, means for holding a rotating lenswith its edge in contact with the grinding face of said wheel, means formoving the edge of said lens across said grinding face, and reversingmeans for changing the direction of travel of said lens, the combinationof means for controlling said reversing means comprising a pair ofspaced fingers disposed respectively adjacent the boundaries of thegrinding face on opposite sides of said lens, a slidable shaftsupporting said fingers in the path of said lens whereby said shaft andfingers are reciprocated by said lens, and means operably connected tosaid shaft for controlling the reversing means whereby the movement ofsaid shaft and fingers in either direction controls the reversing meansfor changing the direction of movement of the lens.

6. A lens edging machine comprising a continuously rotating grindingwheel having a grinding face thereon, means for holding a rotating lenswith its edge in contact with the grinding face of said wheel, means formoving the edge of said lens across said grinding face, reversing meansfor changing the direction of travel of said lens, a pair of spaced,movable fingers disposed respectively adjacent the boundaries of thegrinding face and on opposite sides of the lens, a slidable shaft forsupporting said fingers in the path of said lens, a switch means adaptedto be contacted by said shaft for energizing said reversing means,resilient means engaging with said shaft for resisting axial movement ofthe shaft by said lens whereby movement of the lens against the fingerswill move the shaft against the resistance of the resilient means toactivate the reversing means for changing the direction of movement ofthe lens.

7. A lens edging machine comprising a continuously rotating grindingwheel with a grinding face thereon, holding means for positioning theedge of a lens in contact with said grinding face, moving means fortraversing the edge of the lens across said grinding face, reversingmeans for changing the direction of travel of said lens across saidgrinding face, means for controlling said reversing means comprising apair of spaced, movable fingers disposed respectively adjacent theboundaries of the grinding face on opposite sides of said lens, andsupporting means for holding said fingers in the path of said lensoperably connected to said reversing means whereby movement of thefingers and supporting means in either direction by the moving lensactivates the reversing means for changing the direction of travel ofthe lens across the grinding face of the wheel.

8. In a lens edging machine having a continuously rotating grindingwheel with a grinding face thereon, means for holding the edge of a lensin contact with the grinding face of said wheel, means for moving theedge of the lens across said grinding face, and reversing means forchanging the direction of movement of said lens, the combination ofmeans for controlling said reversing means comprising two spaced,movable fingers disposed respectively adjacent the boundaries of saidgrinding face on opposite sides of said lens, a reciprocable shaftsupporting said fingers in the path of said lens, a switch having twopoles that are alternately activated by the movement of said shaft, twosolenoids electrically connected with said switch so that when saidshaft activates one pole of the switch one of the solenoids will beenergized, and means actuated by 7 the movement of the core of theenergized solenoids for 1,272,474 controlling the reversing means forreversing the travel 2,544,156 of the lens across the grinding face.2,633,678

References Cited in the file of this patent 5 UNITED STATES PATENTS680363 675,936 Dawson June 11, 1901 8 Long July 16, 1918 Hathaway Mar.6, 1951 Smith Apr. 7, 1953 FOREIGN PATENTS Great Britain Oct. 15, 1952

